The present invention relates to a linear guide unit provided with a length measuring system. Such linear guide units are used, for example, in machine tool construction or in transport devices of assembly lines or in woodworking. The length measuring systems allow highly precise positioning of the guide carriage at predetermined positions.
From DE 199 41 587 A1, for example, a linear bearing with a measuring device is known, wherein a guide carriage is arranged so that it can move in the longitudinal direction on a guide rail. The guide carriage is provided on the end with a measuring head. The guide rail is provided on its upper side with a groove, in which a measuring body is inserted. The measuring body is here constructed in one piece with a cover strip, which is held with a non-positive fit in the groove of the guide rail. Alternatively, the measuring body can be adhered to the flat strip. If the measuring body should need to be changed, this is possible by exchanging just the measuring body with the cover strip.
For other known linear bearings with integrated measuring systems, in the condition at the time of delivery, the scale or the measuring body is adhered to the guide rail. In this case, exchanging a measuring body without exchanging the guide rail is possible only with difficulty.